Editing Stool test

{{short description|Medical examination of fecal matter}}
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{{Infobox diagnostic
| name            = Stool test
| image           = Stool transport.JPG
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| caption         = Transport vials filled with human feces for stool testing. Yellow and blue tops for parasite testing, red top for stool cultures and the white top was provided by the patient with the sample.
| pronounce       =  
|purpose          = diagnose if medical condition is present
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| ICD10           = <!--{{ICD10|Group|Major|minor|LinkGroup|LinkMajor}} or {{ICD10PCS|code|char1/char2/char3/char4}}-->
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A '''stool test''' is a medical diagnostic technique that involves the collection and analysis of fecal matter. Microbial analysis (culturing), microscopy and chemical tests are among the tests performed on stool samples.

==Collection==
Stool samples should be sent to the laboratory as soon as possible after collection and should not be refrigerated prior to  by the laboratory.<ref name="medilib 2021">{{cite web | title=Approach to stool microscopy | website=medilib | date=2021-06-02 | url=https://www.medilib.ir/uptodate/show/14001 | language=fa | access-date=2022-08-16}}</ref>

==Visual examination==
The patient and/or health care worker in the office or at the bedside is able to make some important observations.

* Color  
* Texture/consistency—formed
* Classify type of feces (diagnostic triad for irritable bowel syndrome) based on [[Bristol stool scale]]

==Cancer screening==
[[Fecal occult blood test]] and [[fecal immunochemical test]] are the most common stool tests to diagnose many conditions that caused by bleeding in the [[gastrointestinal system]], including [[colorectal cancer]] or [[stomach cancer]].<ref>{{cite web |title=Fecal Occult Blood Test (FOBT) |url=http://www.webmd.com/hw/colorectal_cancer/hw227116.asp}}</ref>  The American College of Gastroenterology has recommended the abandoning of gFOBT testing as a colorectal cancer screening tool, in favor of the [[fecal immunochemical test]] (FIT).<ref>{{cite journal |vauthors=Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM |date=March 2009 |title=American College of Gastroenterology guidelines for colorectal cancer screening 2009 [corrected] |journal=The American Journal of Gastroenterology |volume=104 |issue=3 |pages=739–750 |doi=10.1038/ajg.2009.104 |pmid=19240699 |s2cid=295873|doi-access=free }}</ref>  The newer and recommended tests look for [[globin]], [[DNA]], or other blood factors including [[transferrin]], while conventional [[stool guaiac test]]s look for [[heme]].

Cancers, and to a lesser extent, precancerous lesions, shed abnormal cells into the stool.<ref name="Osborn NK 2005">{{cite journal |last1=Osborn |first1=NK |last2=Ahlquist |first2=DA |date=2005 |title=Stool screening for colorectal cancer: molecular approaches |journal=Gastroenterology |volume=128 |issue=1 |pages=192–206 |doi=10.1053/j.gastro.2004.10.041 |pmid=15633136|doi-access=free }}</ref> Cancers and precancerous lesions ([[Polyp (medicine)|polyps]]) that are ulcerated or rubbed by passing stool also may shed blood into the stool, which can be identified by a hemoglobin assay.<ref name="Osborn NK 2005" />  

The [[American Cancer Society]] and the [[U.S. Preventive Services Task Force]] recommended colorectal cancer screening with a [[fecal immunochemical test]] every year, or  a multi-target stool DNA test for every three years from the age of 45.<ref name=":0">{{cite journal |last1=Tepus |first1=M |last2=Yau |first2=TO |date=20 May 2020 |title=Non-Invasive Colorectal Cancer Screening: An Overview |journal=Gastrointestinal Tumors |volume=7 |issue=3 |pages=62–73 |doi=10.1159/000507701 |pmc=7445682 |pmid=32903904 |doi-access=free}}</ref> Other options include a [[sigmoidoscopy]] or [[virtual colonoscopy]] (CT colonography) for every five years or a [[colonoscopy]] for every 10 years.
[[Fecal occult blood test]] is no longer recommended due to the high false-positive rate as well as the dietary and pharmaceutical restrictions.<ref name=":0" /><ref>{{cite web |title=American Cancer Society recommendations for colorectal cancer early detection |url=http://www.cancer.org/cancer/colonandrectumcancer/moreinformation/colonandrectumcancerearlydetection/colorectal-cancer-early-detection-acs-recommendations |access-date=14 July 2016 |website=www.cancer.org |archive-date=3 December 2016 |archive-url=https://web.archive.org/web/20161203205348/http://www.cancer.org/cancer/colonandrectumcancer/moreinformation/colonandrectumcancerearlydetection/colorectal-cancer-early-detection-acs-recommendations |url-status=dead }}</ref> The [[National Committee for Quality Assurance]] (NCQA) issued an update to the [[Healthcare Effectiveness Data and Information Set]] (HEDIS) for 2017, while the guideline remains for the patients aged 50 or over.<ref>{{cite web |last1=National Committee for Quality Assurance |title=Healthcare Effectiveness Data and Information Set 2017 Volume 2: Technical Update |url=http://www.ncqa.org/Portals/0/HEDISQM/HEDIS2017/HEDIS%202017%20Volume%202%20Technical%20Update.pdf?ver=2016-10-03-114902-317}}</ref>

A multi-target stool DNA test was approved in August 2014 by the FDA as a screening test for non-symptomatic, average-risk adults 50 years or older.<ref name="Food and Drug Administration press release">{{cite web |date=August 11, 2014 |title=FDA approves first non-invasive DNA screening test for colorectal cancer [press release] |url=https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm409021.htm |archive-url=https://web.archive.org/web/20140812180130/http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm409021.htm |url-status=dead |archive-date=August 12, 2014 |access-date=30 June 2015 |website=Food and Drug Administration}}</ref> A 2017 study found this testing to be less [[cost effective]] compared to colonoscopy or fecal occult blood testing.<ref name="Bar2017">{{cite journal |last1=Barzi |first1=A |last2=Lenz |first2=HJ |last3=Quinn |first3=DI |last4=Sadeghi |first4=S |date=1 May 2017 |title=Comparative effectiveness of screening strategies for colorectal cancer. |journal=Cancer |volume=123 |issue=9 |pages=1516–1527 |doi=10.1002/cncr.30518 |pmid=28117881 |doi-access=free|pmc=6879196 }}</ref> Three-year multi-target stool DNA test has been estimated to cost $11,313 per [[quality-adjusted life year]] (QALY) compared with no screening.<ref>{{cite journal |last1=Berger |first1=BM |last2=Shroy |first2=PC |last3=Dinh |first3=TA |year=2015 |title=Screening for Colorectal Cancer Using a Multitarget Stool DNA Test: Modeling the Effect of the Intertest Interval on Clinical Effectiveness. |url=http://www.clinical-colorectal-cancer.com/article/S1533002815001541/pdf |journal=Clinical Colorectal Cancer |volume=15 |issue=3 |pages=e65–e74 |doi=10.1016/j.clcc.2015.12.003 |pmid=26792032 |doi-access=free}}</ref>

==Microbiology tests==
{{see also | Kato technique}}
Parasitic diseases such as [[ascariasis]], [[hookworm]], [[strongyloidiasis]] and [[whipworm]] can be diagnosed by examining stools under a microscope for the presence of worm larvae or eggs. Some bacterial diseases can be detected with a stool culture. Toxins from bacteria such as ''[[Clostridioides difficile (bacteria)|Clostridioides difficile]]'' (''C. diff'') can also be identified. Viruses such as [[rotavirus]] can also be found in stools.<ref>{{cite web|url=http://www.webmd.com/hw/lab_tests/hw5738.asp|title=Stool culture}}</ref> Other stool tests involve the detection of antibiotic resistance as to guide appropriate therapy, e.g. Clarithromycin resistance of [[Helicobacter pylori]] represents a major challenge in eradication therapy but the responsible bacterial genomic markers can be detected in stool using PCR technology and thus can guide the prescription of the appropriate antibiotics to specific patients.<ref> {{cite journal | vauthors = Mommersteeg MC, Nieuwenburg SA, Wolters LM, Roovers BH, van Vuuren HA, Verhaar AP, Bruno MJ, Kuipers EJ, Peppelenbosch MP, Spaander MC, Fuhler GM | title =  The use of non-invasive stool tests for verification of Helicobacter pylori eradication and clarithromycin resistance. | journal =  United European Gastroenterol J | volume = 11 | issue = 9 | pages = e894-903| date = November 2023 | pmid = 37854002 | PMC = 10637120 | doi = 10.1002/ueg2.12473 | doi-access = free}}</ref>

==Chemical tests==
A [[fecal pH test]] may be used to determine [[lactose intolerance]] or the presence of an infection.<ref>{{cite web|url=http://www.medicinenet.com/stool_acidity_test/article.htm|title=Stool Acidity Test - MedicineNet.com}}</ref> [[Steatorrhea]] can be diagnosed using a [[fecal fat]] test, which checks for the malabsorption of fat.<ref>{{cite web|url=https://www.nlm.nih.gov/medlineplus/ency/article/003588.htm|title=MedlinePlus Medical Encyclopedia: Fecal fat}}</ref>

Faecal elastase levels are becoming the mainstay of pancreatitis diagnosis.

==See also==
{{Portal|Medicine}}
* [[Rectal examination]]
* [[Faecal calprotectin|Calprotectin examination]]

==References==
{{Reflist|2}}

{{Digestive system procedures}}
{{Authority control}}

[[Category:Stool tests| ]]